Separator



March 9, 1954 A. F. BARRY 2,671,322

SEPARATOR Filed Ost. 16, 1950 2 Sheets-Sheet l A TTORNE K5 A. F. BARRY March 9, 1954 SEPARATOR 2 Sheets-Sheet 2 Filed Oct. 16, 1950 .Arf/wr F, Bor/* y INVENTOR.

By( MAJ is formed by a horizontally disposed chamber, whereby the heat applied to the warm zone will not materially affect the temperature of the cold zone and also whereby separation of the zones can be maintained without the necessity of increasing the vertical height of the separator beyond practical limits.

A particular object is to provide a separator, of the character described, wherein the separator vessel is arranged so that the liquid level control device in the warm zone is disposed out of the path of the precipitating condensed liquids and hydrates to assure continuous ecient operation of the separator.

Other objects will appear hereinafter.

The construction designed to carry out the invention will be hereinafter described together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is an isometric view of a separator, constructed in accordance with the invention,

Figure 2 is an enlarged longitudinal sectional view of the same,

Figure 3 is a transverse vertical sectional view, taken on the line 3-3 of Figure 2, and

Figure 4 is a partial sectional detail of one end of the warm zone chamber and illustrating a slight modification of the invention.

In the drawings, the letter A designates the improved separator which includes a horizontally disposed vessel Iii which is preferably circular in cross-section and which has its ends closed by the usual end members II and I2 (Figure 2). A vertically extending tower I3, also cylindrical in cross-section, but preferably of a smaller dia-rneter than the diameter of the vessel, extends upi.

Wardly from one end of the vessel and has a base flange I4 which is welded or otherwise secured to the exterior of the vessel. The upper end of the tower I3 is closed by a dome or cap I5 while the lower end of the vessel communicates with the interior of the vessel through an opening I6 formed in the wall of said vessel. The vessel is mounted on suitable supports I'l which are welded or otherwise secured to the lower portion of the vessel and extend transversely thereof. The separator is adapted to receive a high pressure gas stream which under its pressure and temperature is saturated with water and hydrocarbon components in the vapor phase and which also may contain hydrocarbons in the liquid phase. Such a stream may be one which has been conducted from a high pressure gas distillate well from which free liquid water has been removed. The stream which will hereinafter be referred to as a gas stream is conducted to the separator through an inlet pipe or conductor I8, which conductor has connection with a choke device I9. The device I9 may be an ordinary adjustable choke, and after passing through the choke orifice (not shown) within the device I9, the stream is directed to a short inlet pipe 22 into the interior of the upper portion of the tower I3. It is preferable that the iinner end of the pipe 20 which is disposed within the interior of the tower be directed downwardly and also bent at somewhat of an angle with repect to the axis of the tower, whereby the incoming stream is directed downwardly in somewhat of a swirling or generally tangential path within th tower, as is clearly shown in Figure 2.

The choke device I9 is provided for the purpose of reducing the pressure of the gas stream to a point which will cause cooling of the stream below the normal hydrate formation point. The gas stream flowing through the conductor I8 is usually under relatively high pressures in the order of 3,000 to 4,000 pounds and in passing through the choke device I9, the pressure is reduced downwardly to a pressure in the order of 1,000 pounds. This pressure reduction results in cooling the stream to a point below that at which hydrates will form so that as the stream is introduced into the tower, the low temperature creates a cold zone within the interior of the tower. The hydrates which are formed in the stream by the extreme cooling action, as well as the hydrocarbon components which are liquefied as a result of said cooling, precipitate downwardly within the cold zone and ultimately precipitate into the interior of the horizontally disposed vessel I0. The cold gas from which the hydrates and condensed liquids precipitate then flows upwardly within the cold zone of the tower I3 and escapes therefrom through an outlet pipe 2i; as illustrated in Figure 2, the outlet pipe has a vertical leg 2Ia having an open upper end so that the gas passes upwardly above the leg 2Ia and then downwardly and outwardly through pipe 2l.

It is important to the present invention that the pressure reduction effected .by the device I9 be suioient to lower the temperature of the stream well below the hydrate formation point, and thus, the water within the stream is condensed and hydrates are formed. The extreme cooling so effected results in the condensation of certain of the hydrocarbon components and thus, additional separation of such hydrocarbon components is eected.

The hydrates and liqueed hydrocarbon components are pertmitted to precipitate downwardly into the vessel I0 and within this vessel a liquid body is maintained. This body of liquid, the level of which is controlled by a suitable float Y B, is maintained at a relatively warm temperature by means of a heating coil 22. As is clearly shown in Figures 2 and 3, the heating coil 22 has an inlet 23 and an outlet 24 which extend through the end wall I2 of the vessel. A suitable warming fluid may be circulated through the coil 22 in order to warm the body of liquid maintained in the vessel I0. It is noted that the heat applied to the body of liquid is only sufficient to warm this body to a temperature just above the melting point of the hydrates which precipitate downwardly into the liquid from the tower I3. In this way there is substantially no heat transferred into the cold zone, which is formed within the interior of the tower I3 and thus the gas which is separated in said cold zone is not heated in its passage through said zone. With this arrangement the gas escaping through the outlet 2I is of substantially the same temperature as the gas entering the inlet pipe 20 and by preventing any heating of the gas there is no danger of said gas picking up any of the liquids which have been condensed by the pressure reduction and cooling steps. Although any source of heating fluid may be provided for the coil 22 it has been found that the ow stream may be circulated through the coil 22 prior to its passage to the inlet conductor I8 for at this time the high pressure gas stream as it flows from a well will be at a relatively warm temperature. By circulating the flowl streaml through the coil.

the necessity for providing auxiliaryheat for' said coil is. eliminated which simplifies the construction and results in an economic saving.

It is desirable that the liquidl level' oi the` body of liquid within the vessel be just above the coil 22 so that said coil is immersed. within. the. body of liquid and as indicated in Figure 2 the level is maintained at that indicated by the letter L. This level is controlled by an angular outlet. pipe 25 which is disposed at that end of. the vessel remote from the tower I3. Thel outlet pipe 25 has the vertical. leg. 25o and as. the liquid level reaches the upper end ofsaid vertical leg,.an overflow occurs which permits the liquid to ow to an outlet conductor 21E.. The iioat. LB in Figure. 2 is provided for the purpose of discharging the water separately from the hydrocarbon liquids within the vessel I0.. Although this iioat may be of any desired construction the iloat is illus.` trated as one which actuates a torque tube such as shown in the application of Asbury S. Parks, Serial No. 105,203, filed July 16, 19.49. As. illustrated the float structure comprises a solid oat member 21 suspended from a rod 28 which has its upper end connected to a suspending arm 29 (Figure l). The arm 29 has its opposite. end connected with a torque tube 30 which operates ay pilot control mechanism 3l. The upper portion of the rod 28., the arm 29 and the torque. tube are housed in suitable piping 32 which piping is, of course, welded at 33` to the vessel I9. The pilot control mechanism 3| controls the application of pilot pressure from a. pilot line 3d through a line 35 which extends to a motor valve 36. The motor valve is mounted within a water outlet pipe 31 which extends from a sump 33 provided in the bottom of the vessel Ill.

To provide a quiescent zone in which the float may operate the rod 28 and float. 21 are preferably surrounded by a sleevey 39 having` slots or perforations 4o therein. The sleeve has its ends terminating short of the tank wall and is mount.- ed in position by suitable straps 4I.

It is evident that the; iloat 21 will control the level of the water which, of course, settles to the bottom of the vessel IB and thus a predetermined water level will be.` maintained at; all times within the vessel. Rising of the water level will cause the oat 21 to aotuate the pilot control mechanism Si and thereby open valve 35 and permit. discharge of water until the level falls to the desired point, at which time the. valve 36 is closed. The level L of the hydrocarbon liquid is maintained by means of the vertical leg 25a of the angular outletl pipe '25..

A suitable relief valvev 42 ismountedv in the upper end of the vessel ICIv and has a suitable stand pipe 43 extending upwardly`r therefrom. A safety head 44 having an upwardly extending stand pipe 45 is also connected in the upper end of the tank. A similar safety head 46 is mounted in the dome or upper cap l5;y of the tower I3.A

In the operation of the. unit, the gas stream which may be a stream flowing under high pressure from a gas distillate well and froml which free water has been removed is directed through the conductor i8 into the cold zone created within the interior of the tower I3. through the inlet pipe 2o. In passing through the choke device I2 the pressure is reduced to the point where.l the cooling or the stream due to the pressure reduction is to a point below that at. which hydrates form. The extreme coolingl occasioned' by the temperature drop. results in a condensationV of hydrocarbon components. and also results'. in. a

condensation and freezing or' the watery particles tol form hydrates. The. heavier condensed hydrocarbon components and the heavier hydrates precipitate downwardly through. the tower. I3 and fall into the body or liquid' which is maintained withinI the vessel I3. The gas which is separated from the liquids: under the extremely low temperature in the tower I3 passes upwardly in. the tower and escapes` through the outlet pipe 3i. The precipitating hydrocarbons and hydratesy fall intothev body of liquid within the vessel I0 which is maintained at a temperature above the hydrate point so that the hydrateswill' thereby be melted and liquefied so as to reduce them to water. The water will, of course, settle within the lower portion of the vessel I 0 and will be intermittently discharged inY accordance with the operation of the discharge valve 36-V response to the lloat deviceB. The level L of the hydrocarbon liquids withinthe vessel tu is maintained by the riser pipe 25ct` andsa-id liquids are discharged from the vessel throughA the outlet line 26.

It is pointed out that the level L at which the body of liquid within the vessel I0 is maintained is slightly below the upper portion of thetank with the result that a slight space between said level and the upper wall of the tank maintained. There is a minimum of area of com' munication between the towerv I3 and the. vessel which means that the heat'applied to the body of liquid is not transferred into the cold zone formed within the interior of the tower, and with this arrangement the gas may leave the tower without any material change in itsl temperature;

Since the gas is extremely cold as it leaves the tower I3 it is actually underesaturated with water vapor and therefore asv it moves from the tower and into the usual transportingl lines, its

. temperature will increase to further increase its liquid carrying capacity. Because the gas will never again reach the low` temperature which it had within the tower I3, there is no subsequentl danger of freezing in the lines beyond the tower I3 because in order for any liquid to' be released from the gas it would be necessary toV dropv the temperature of this gas belowthat of the cold zone in the tower.

It is wellv known that hydrocarbon recovery is increased at lower temperatures and the` present separator makes it possible to recover the maximum amount of hydrocarbon componentsv from the gas stream. The separator alsoV removes a maximum amount of water from thegas and`actuallyv produces a gas which is under-saturated at the pressure and temperature of the separator; The improvedi results are obtained by maintaining the warm zone-within tlfievessell and the cold zone within the tower so that substantially no heat is applied to the gas after separation; the heat applied to the warm. body" of liquid within the vessel I0 is above the hydrate point but is also suicient to assure melting of thehydrates'. It is, therefore, possible to-obtain maximum hydrocarbon recoverywhil'e substantially dehydrating thel gas to the point where it may meetI pipe line specifications respectv toi water content.

In certain instances it mayY not. be desirableY to dump the water separately` from the hydrocarbon liquids and' in such case theevessel lll'i'sfmodied as shown in Figure 4'. In this eventv theangul'ar outlet pipe 25 has its outerA end plugged by a, suitable plug 41T, suchplug being; substituted for the outlet conductor 26. The floot II is connected'.

29 and this locates the float at the upper portion of the vessel so that said oat controls the liquid level L in the same manner that the overflow leg 25a controls such level in the first form. The oat 21 in the form shown ,in Figure 4 will control the discharge valve 36 and all liquids will be removed from the vessel through the line 31. It is pointed out that although the sump 38 is desirable, particularly in the form where the interface between the water and the hydrocarbon liquids is to be maintained, this sump is not essential and may be omitted; the outlet pipe 31 would in such instance be connected directly in the bottom of the vessel I0.

From the foregoing, it will be evident that an improved separator for effecting the separation of liquids from high pressure gas streams is provided. The stream is directed into a cold zone following pressure reduction and said cold zone is maintained at a point below the normal hydrate formation point at the separator pressure. This extreme cooling of the gas stream increases the recovery of hydrocarbons and at the same time forms hydrates which are precipitated from the cold zone into a warm zone which might be said to be remote from the cold zone. In the warm zone a warm body of liquid maintained at a temperature above the hydration point is provided, and this liquees the hydrates and permits the removal thereof as water. The construction is such that there is a minimum heat transfer between the warm zone and the cold zone with the result that the gas stream after being cooled is never reheated but leaves the cold zone at substantially the same temperature as said zone. It is this particular arrangement which assures substantial removal of the water from the gas.

The heating coil which extends throughout the major portion of the vessel is preferably immersed within the body of liquid and may be provided with an auxiliary heating medium; however, if desired the relatively warm high pressure gas stream may be circulated through the coil to provide the required heat for the body of liquid prior to its passage to the inlet conductor I8. It is noted that the oat mechanism is preferably located at that end of the Vessel I9 which is remote from the tower I3, and this assures that the precipitating hydrates and hydrocarbon components do not contact the float and therefore can never interfere with iioat operation. By constructing the separator with the vessel I extending horizontally and the tower I3 extending vertically, the overall height of the vessel is minimized. It is obvious that if the vessel I0 is vertically disposed below and as a continuation of the tower I3, the complete separator would have to have considerable height because it is necessary that the warm zone be sufliciently removed from the cold zone to prevent any substantial heating of the separated gas. It is also evident that if the vertical type vessel were provided the float mechanism would be disposed in the path of the precipitating hydrates and liquids and there might be a possibility of interfering with accurate liquid level control.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the inventionwj 8 'Having described the invention, I claim:

1. A separator including, a horizontally disposed vessel, a vertically disposed tower extending upwardly from the vessel and having its lower end communicating with the interior of the vessel, an inlet conductor connected in the upper portion of the tower for conducting a gas stream into the tower, means in the conductor in advance of the point of entry of the gas stream into the tower for cooling the stream to condense liquids and form hydrates which precipitate downwardly through the tower into the horizontally disposed vessel, a tubular element having openings in its wall mounted within the vessel at a point out of alignment with the vertical tower and forming a quiescent float chamber, a float element movable within the float chamber and responsiveto the liquid level in said chamber, a controller assembly actuated by the iloat for maintaining a predetermined liquid level in said vessel, heating means in the horizontal vessel for heating the body of liquid therein, a gas outlet extending from the upper portion of the tower, and a liquid outlet extending from the lower p0rtion of the vessel.

2. A separator as set forth in claim 1, wherein the heating means comprises a coil within the vessel having its axis substantially aligned with the axis of the vessel and of a diameter slightly less than the diameter of the vessel, saidA coil extending longitudinally throughout the major portion of the vessel.

3. A separator as set forth in claim l, wherein the float maintains a predetermined level of one liquid within the vessel, and an overflow pipe within the vessel also out of alignment with the tower for maintaining the level of a second liquid within the vessel.

4. A separator including, a vessel having an inlet conductor connected in its upper portion for conducting a gas stream into the vessel, means in the conductor in advance of the point of entry of the gas stream into the vessel for cooling the stream to condense liquids and form hydrates which precipitate downwardly through the vessel, a tubular element having openings in its wall mounted within the vessel at a point out of vertical alignment with the point at which the gas stream enters the vessel, said tubular element forming a quiescent float chamber, a float element movable within the float chamber and responsive to the liquid level within said chamber, a controller assembly actuated by the float for maintaining a predetermined liquid level in said vessel, heating means in the vessel for heating the body of liquid therein, a gas outlet extending from the upper portion of the vessel, and a liquid outlet extending from the lower portion of the vessel.

ARTHUR F. BARRY.

References Cited in the le of this patent UNITED STATES PATENTS l Date 

